edh wrote:
Those values are all for the system, not the CPU itself.
CA_Steve wrote:
A couple of things to think about:
- When measuring CPU power consumption, most reviewers are measuring system power use and not at the component as edh pointed out.
- When measuring power consumption, most reviewers are measuring at the AC wall socket and not the DC power drawn from the PSU. To find out the DC draw, you need to know the PSU's efficiency at that particular load.
Well. That removes the inconsistency I thought I was seeing in the numbers.
Thank you both for giving me the benefit of your experience.
But who would have thought that a
processor review would report power consumption for the
whole system? I mean, it’s a nice number to know, but when I’m doing a power and cooling design, I want to know idle, active and peak current draws for each component on each rail, and how much heat each component dissipates under various operating conditions.
The more I look, the harder this information is to find. So, what, do they expect you to do – plug together a bunch of arbitrary components, chosen based on misleading reviews and incomplete specifications, and pray they all play nice together?
Well, maybe not quite. Here’s an interesting overview, though it dates from 2009:
Calculating Power Consumption Of The Entire System.
edh wrote:
Please can you give some link to where you found a 30W hard disk this side of the 1970s.

No modern hard disk uses that power. 10W is a fair load number for a modern HDD and SSDs are any a couple of Watts even at load.
I stand corrected. Going back to the spec sheets, I find 11W for the Western Digital Caviar Black, 3W for the OCZ Vertex 3, and no number for the LG BH14NS40, so I’ll take it to be 9W, the midpoint of Tom’s range of 5-12W.
CA_Steve wrote:
Add the GTX 680 (244W), and maybe 20W for your additional components, and you get 477W (DC) as a stressed load...and maybe 425W while gaming*. Again, if you overvolt/overclock it needs to be addressed.
Putting all the updated numbers together, I get
mobo: 50 W x 1 = 50 W
cpu: 130 W x 1 = 130 W
gpu: 244 W x 1 = 244 W
ram: 0.5 W x 16 = 8 W
disk: 11 W x 1 = 11 W
ssd: 3 W x 1 = 3 W
dvd: 9 W x 1 = 9 W
fan: 3 W x 6 = 18 W
pump: 30 W x 1 = 30 W
overall total: 503 W
So now we are only 26W apart, and that’s close enough for me.
CA_Steve wrote:
For grins, here's a couple of reviews of the GTX 680 where the test setups were similar to yours:
X-bit labs had 456W (AC) while running an overclocked and overvolted i7 and overclocked GPU under Metro 2033. The PSU used is ~85% efficient at this load, leading to ~390W (DC) load.
Hot Hardware saw 393W (AC) under heavy workload at stock clocks. They fail to say what PSU is used. Best case, it's Platinum and running at max efficiency..call it 92%. This implies DC load of 362W.
I can’t follow your link to X-bit Labs, because it crashes my browser, but yes, the system reviewed by Hot Hardware looks like it should be within 100W of what I have in mind.
That’s a nice reality check; thanks again.
edh wrote:
Please don't buy these motherboards anyway! 'High end' gaming motherboards are just marketing gimmicks. Take the top Intel chipset, lob some cheap addons at it, give it horrid colours, gimmicky features and a higher price and people will buy it, just because it's more expensive. Doesn't make it any better in actual use.
CA_Steve wrote:
I hope this isn't a gaming build...SNB-E adds no value for gaming.
No, this is not primarily a gaming build; its mostly for mathematical modeling and combinatorial algorithms. The GTX 680 is for its CUDA cores. However, it would be nice to play the odd game, too.
While the 9360X is overkill for today, I want to be able to run the box for years without further hardware upgrades. I like to wait until I can get at least a factor of 10 performance improvement before I move from one system to the next, meaning 6 to 7 years. The only major component I may have to replace in that period is the hard disk.
I may want to open the box at the halfway point to speed up the clocks, though.
And I still have no idea what longevity to expect of a water cooling set-up.
What are your thoughts on these issues?